This invention relates to intrusion sensors, and more particularly to pre-wired window panes.
Intrusion devices using mechanical devices activated by the unauthorised opening of doors and windows were the first to be employed. Electrically activated devices replaced the mechanical as the field matured. Currently external metallic tape attached to the external window periphery and varnished for protection from damage is widely used. Furthermore, U. S. Pat. No. 4,228,425 granted Oct. 14, 1980 to William C. Cooke shows a laminated structure carrying conductive elements in a special glass and plastic laminate thus limiting its general application and adding cost. A system employing wires in parallel elongated panel is used to detect unauthorized breach of walls and other structure is shown in U.S. Pat. No. 4,234,875 granted Nov. 18, 1980 to William H. Williams. A fiber optic sensor embedded in a transparent panel is shown in U.S. Pat. No. 4,376,460 granted Jan. 4, 1983 to Henri Hodara. These systems can cause obstruction of view through the window pane and require a regular pattern of wires which could allow easy removal of portions of the window.
A need exists for a transparent conductive pre-wired window arrangement which is generally available, economical and resistant to damage.